Technological Feasibility of Lattice Materials by Laser-Based Powder Bed Fusion of A357.0

Abstract

Lattice materials represent one of the utmost applications of additive manufacturing. The promising synergy between additive processes and topology optimization finds full development in achieving components that comprise bulky and hollow areas, as well as intermediate zones. Yet, the potential to design innovative shapes can be hindered by technological limits. The article tackles the manufacturability by laser-based powder bed fusion (L-PBF) of aluminum-based lattice materials by varying the beam diameter and thus the relative density. The printing accuracy is evaluated against the distinctive building phenomena in L-PBF of metals. The main finding consists in identification of a feasibility window that can be used for development of lightweight industrial components. A relative density of 20% compared with fully solid material (aluminum alloy A357.0) is found as the lowest boundary for a 3-mm cell dimension for a body-centered cubic structure with struts along the cube edges (BCCXYZ) and built with the vertical edges parallel to the growth direction to account for the worst-case scenario. Lighter structures of this kind, even if theoretically compliant with technical specifications of the machine, result in unstable frameworks.

Mechanical performance of additively manufactured uniform and graded porous structures based on topology-optimized unit cells

“…45,46 Moreover, the minimum feature dimension for selective laser melting (SLM) of metal alloys is quantified in literature studies as 0.2 mm. 47,48 So, to prevent the struts of the optimized unit cells from growing too thin during the element removal process, a member size constraint of 300 microns (0.3 mm) is considered. The convergence criterion is set to 0.001 based on the change in the objective function from one optimization iteration to the next optimization iteration.…”

Investigation of Compressive and Tensile Behavior of Stainless Steel/Dissolvable Aluminum Bimetallic Composites by Finite Element Modeling and Digital Image Correlation

“…The difference between these three face-centered cubic unit cells can be seen in Figure 1a,b,e. BCC (body-centered cubic), BCC,Z (bodycentered cubic with Z-struts), gyroid and rhombic were also analyzed [2,3,12,29,[33][34][35] through compressive, tensile, and fracture testing. They concluded that F2CC,Z has a higher load capacity, and gyroid can be very useful in applications requiring high stiffness.…”

Steering column support topology optimization including lattice structure for metal additive manufacturing

“…The lattice structure itself becomes a support for the outer shell. The size of the tetrahedral cells is small enough to consider the lattice beams as selfsupporting, as pointed out by Sola et al 45 Some of the well-known optimization methods for AM were not considered in this study. For example, this work did not address the overhang constraints defined in Patterson et al 17 and Jiang et al, 18 as we accepted the presence of structural supports in this study.…”